Conventionally, various metal fine particles are dispersed in various coating agents so as to impart various properties such as mechanical properties, chemical resistance, high refractive index, antistatic properties, ultraviolet ray and infrared ray shielding properties, and excoriation resistance to a cured film obtained by applying the coating agent to be cured, or furthermore as a pigment or the like.
In such a coating agent, the metal fine particles may aggregate, depending on the kind of the metal fine particles, a solvent, a binder resin, or the like, which is blended. Thus, it has been proposed that a dispersant is added to the coating agent so as to excellently disperse the metal fine particles.
To be specific, a pigment dispersing resin having, as an active component, a copolymer obtained by polymerization of (1) 5 to 60 weight % of (meth)acrylate having a saturated alicyclic group composed of two or more rings; (2) 5 to 50 weight % of C10 to C35 alkyl (meth)acrylate; and (3) 0.1 to 30 weight % of polymerizable monomer having at least one functional group selected from a hydroxyl group, a carboxyl group, a tertiary amino group, a quaternary ammonium base, a sulfonate group, and a phosphate group, and a coating composition containing the pigment dispersing resin, a binder resin, a solvent, and a pigment have been, for example, proposed (ref: the following Patent Document 1).
Also, a metal oxide fine particle dispersant, which is a reaction product prepared by allowing a polymer of a vinyl compound having, in a molecule, an epoxy group to be subjected to addition reaction with a carboxyl group-containing (meth)acrylic compound and has a (meth)acrylic equivalent of 200 to 360 g/eq., a hydroxyl value of 150 to 270 mgKOH/g, and a weight average molecular weight of 8000 to 50000, has been, for example, proposed (ref: the following Patent Document 2).